Fosaprepitant, chemically [3-{[(2R,3S)-2-[(1R)-1-[3,5-bis(trifluoromethyl)phenyl]ethoxy]-3-(4-fluorophenyl)morpholin-4-yl]methyl}-5-oxo-2H-1,2,4-triazol-1-yl]phosphonic acid and has the structural formula:

Fosaprepitant dimeglumine is an antiemetic drug, administered intravenously. It is a prodrug of aprepitant. Fosaprepitant dimeglumine is commercially available as a prescription medicine from Merck & Co, under the trade name EMEND® in US and IVEMEND® in Europe.
Fosaprepitant dimeglumine and its process were disclosed in U.S. Pat. No. 5,691,336.
PCT publication no. WO 2010/018595 disclosed a process for the purification of fosaprepitant dimeglumine. According to the publication, fosaprepitant dimeglumine can be prepared by subjecting the solution of dibenzyl {3-[2(R)-[(1R)-1-[3,5-bis(trifluoromethyl)phenyl]ethoxy]-3 (S)-(4-fluorophenyl)morpholin-4-yl]-5-oxo-4,5-dihydro-[1,2,4]-triazol-1-yl} phosphonic acid (herein after referred as dibenzyl fosaprepitant) in methanol or tetrahydrofuran to hydrogenation in the presence of palladium carbon and N-methyl-D-glucamine.
PCT publication no. WO 2011/045817 disclosed a process for the preparation of fosaprepitant dimeglumine. According to the publication, fosaprepitant dimeglumine can be prepared by subjecting the solution of dibenzyl fosaprepitant in a solvent such as methanol, ethanol, isopropanol, methyl tert-butyl ether or tetrahydrofuran to hydrogenation in the presence of palladium carbon and N-methyl-D-glucamine.
It has been found that the fosaprepitant dimeglumine produced according to the prior art procedures contains palladium content of above 30 parts per million (ppm). The desired product for reduction of tolerated residual concentration to single digit ppm. There is a need for a reproducible process for the preparation of fosaprepitant dimeglumine.
Thus, an object of the present invention is to provide a novel process for reducing palladium content in fosaprepitant dimeglumine.